The present invention relates to a method and apparatus for purifying water.
The production of high quality water from wastewater or seawater requires a high degree of removal of soluble and/or suspended material.
According to present water treatment practices, conventional wastewater facilities remove suspended material continuously from wastewater by sedimentation, generally in tanks designed to provide sufficient time to permit suspended material to settle to the bottom of the tank. The settled solid material, commonly referred to as sludge, can be continuously or intermittently withdrawn. This basic settling procedure is relatively inefficient, requiring large quantities of both time and space.
Other current practices for the separation of salts from water require great quantities of energy to separate the water from the salts. Distillation, involving boiling the water, or membrane separation, involving forcing the water under pressure through a semipermeable membrane, consume large amounts of energy in return for purified water.
A variety of devices have been used in the past for obtaining pure water by a flocculation technique.
For example, Kalb, U.S. Pat. No. 1,777,849, discloses an apparatus for separating suspended particles of solid matter from water having a plurality of walls forming funnel-shaped baffle members. On the bottom of the apparatus is an outlet through which accumulated solid matter may be removed.
Zuckerman, in U.S. Pat. No. 3,635,346, discloses a solids removal device for treatment of water and wastewater. The device is provided with a vertical settling chamber having a final settling zone adjacent the upper end of the settling chamber including a plurality of inverted frustroconical settling plates of increasing diameter arranged one within another and defining annular conduits of upwardly increasing cross-sectional area therebetween.
Allen, U.S. Pat. No. 942,697, discloses an apparatus for separating solid matters from the liquid in which they are suspended. The apparatus comprises a liquid containing tank and an inverted separating cone suspended in the liquid in the tank. Means are provided to let relatively cleaner water cascade over the edge and into an adjacent tank.
However, none of the above-described patents discloses a method or apparatus for removing dissolved salts from seawater or wastewater by a flocculation technique.